However, About 70% of HER2-positive breast cancer patients, indeed in spite of the fact that they at first react to trastuzumab or trastuzumab conjugate regimens, create resistance inside one year of treatment start (3), indicating that although introduction of anti-HER2-based trastuzumab represents a striking advance, resistance to trastuzumab therapy leading to recurrence still limits the survival of HER2-positive breast cancer patients. This evidence concerns the gene ERBB2 and breast cancer.